Heat dissipation device for electronic component

ABSTRACT

A heat dissipation device (2) for an electronic component is disclosed. The heat dissipation device includes a heat dissipating component (20) disposed on a first side of the electronic component (1); at least one elastic element (30) arranged on a second side of the electronic component (1) opposite the first side; a pressure plate (40) arranged such that the at least one elastic element (30) is located between the pressure plate (40) and the electronic component (1), the pressure plate (40) being connected to a fixed structure to apply pressure to the electronic component (1) via the at least one elastic element (30) in the direction of the heat dissipating component (20). An AC-DC converter or a DC-AC converter or a DC-DC converter comprising the heat dissipation device, and a motor vehicle comprising the above converter are also disclosed.

TECHNICAL FIELD

The present invention relates to a heat dissipation device for anelectronic component, such as a power electronic component fitted in amotor vehicle and used for an AC-DC converter or DC-AC converter orDC-DC converter, ensuring good thermal contact between the heatdissipation device and the electronic component.

BACKGROUND ART

The operating temperature of an electronic component directly affectsits own reliability. For example, in a power conversion circuit of anAC-DC converter or DC-AC converter or DC-DC converter, a powersemiconductor device serves an important function, and the operatingstate thereof directly affects the reliability of operation of theentire apparatus. During use, the power semiconductor device willconsume a portion of energy and convert this to heat, with the resultthat the power semiconductor device heats up, and the junctiontemperature rises. When the junction temperature exceeds a safetythreshold, the current will increase sharply, and this may even cause atransistor to burn out. Thus, heat needs to be rapidly released to thesurroundings by means of a heat dissipation device, to lower theoperating temperature of the electronic component.

To ensure stable operation of the heat dissipation device, good thermalcontact between the heat dissipation device and the electronic componentneeds to be maintained.

The use of a pressure plate and bolts to maintain contact between theheat dissipation device and the electronic component is known in theprior art. Specifically, the pressure plate is placed above theelectronic component, and connected to a heat dissipation component bymeans of bolts at suitable positions, such that the electronic componentis pressed tightly against the heat dissipation component. The mostobvious drawback of this solution is that the rigid action force of thepressure plate is applied to the electronic component directly, and thismight cause damage to the electronic component, which has a ratherfragile structure.

The use of an elastic clip loaded with prestress to maintain contactbetween the heat dissipation device and the electronic component is alsoknown in the prior art. Specifically, one end of the elastic clip isfixed to a fixed structure such as the heat dissipation component, andthe other end applies an elastic action force to the electroniccomponent, to bias the electronic component towards the heat dissipationcomponent. Although this solution can avoid the application of a rigidaction force to the electronic component, the elastic clip might developfatigue as time passes under the action of a thermal load, causing areduction in the elastic action force, with the result that stablecontact between the heat dissipation component and the electroniccomponent cannot be maintained.

SUMMARY OF THE INVENTION

The object of the present invention is to at least overcome theabovementioned shortcomings in the prior art, maintaining good thermalcontact between the heat dissipation device and the electronic componentand reducing damage to the electronic component.

According to one aspect of the present invention, a heat dissipationdevice for an electronic component is proposed, wherein the heatdissipation device comprises: a heat dissipating component disposed on afirst side of the electronic component; at least one elastic elementarranged on a second side of the electronic component opposite the firstside; a pressure plate arranged such that the at least one elasticelement is located between the pressure plate and the electroniccomponent, the pressure plate being connected to a fixed structure toapply pressure to the electronic component via the at least one elasticelement in the direction of the heat dissipating component.

This configuration according to the present invention can avoid thedirect application of a rigid action force to the electronic component,preventing the electronic component from experiencing local concentratedstrain and thereby being damaged. In addition, since the pressure plateis connected to the fixed structure, as time passes, the elastic elementcan still apply a sufficient elastic action force to the electroniccomponent, thereby forming stable and reliable thermal contact betweenthe electronic component and the heat dissipating component.

In some embodiments, the electronic component is accommodated in ahousing and electrically connected to a printed circuit board, whereinthe fixed structure is a portion of the heat dissipating component or ofthe housing or of the printed circuit board.

In some embodiments, the pressure plate is firmly attached to the fixedstructure. It is possible to use an almost permanent connection (e.g.welding, adhesive, riveting, etc.), or a removable connection with oneor more fasteners (e.g. a screw, bolt, snap-fit connection, etc.).

In some embodiments, the at least one elastic element is plate-like withan arcuate shape overall, and comprises a top portion and two branchportions extending from the top portion.

In some embodiments, the at least one elastic element is a coil springor an elastic pad.

In some embodiments, the pressure plate or the housing comprises a firstpositioning structure configured to cooperate with a second positioningstructure of the at least one elastic element.

In some embodiments, the first positioning structure is a notch in thehousing, the second positioning structure is a protrusion of the elasticelement, and the protrusion of the elastic element is configured to bereceived in the notch of the housing.

In some embodiments, the first positioning structure is a recess formedin the pressure plate, the second positioning structure is the topportion of the elastic element, and the top portion is configured to bereceived in the recess of the pressure plate.

In some embodiments, the heat dissipation device further comprises aheat conducting layer arranged between the heat dissipating componentand the electronic component.

In some embodiments, the heat dissipation device further comprises anelectrical insulation sheet arranged between the at least one elasticelement and the electronic component.

In some embodiments, the at least one elastic element is made of metal.

In some embodiments, the electronic component is a MOSFET.

According to another aspect of the present invention, an AC-DC converteror a DC-AC converter or a DC-DC converter comprising the heatdissipation device described above is proposed.

In some embodiments, the AC-DC converter or DC-AC converter or DC-DCconverter comprises a housing, wherein the fixed structure is a portionof the housing, or the fixed structure is a portion of the heatdissipating component and the heat dissipating component is connected tothe housing. Since the fixed structure is formed as a portion of thehousing, or the fixed structure is formed as a portion of the heatdissipating component and the heat dissipating component is connected tothe housing, the pressure plate is directly or indirectly fixed to thehousing of the electronic apparatus. This is especially advantageous inthe case where the electronic apparatus is an onboard electronicapparatus, such as an onboard AC-DC converter or DC-AC converter orDC-DC converter. This is because the running of a motor vehicle will beaccompanied by vibration of the onboard electronic apparatus; suchvibration might cause loosening of the thermal contact between theelectronic component and the heat dissipating component, therebyweakening the heat dissipation effect. Having the pressure platedirectly or indirectly fixed to the housing of the electronic apparatusenables the positioning of the pressure plate to be more reliable,thereby resisting the adverse effect of vibration on thermal contactmore effectively.

According to another aspect of the present invention, a motor vehiclecomprising the AC-DC converter or the DC-AC converter or the DC-DCconverter described above is proposed.

BRIEF DESCRIPTION OF THE DRAWINGS

Those skilled in the art will gain a better understanding of the contentdisclosed herein through the following drawings, which can reflect moreclearly the advantages of the content disclosed herein. The drawingsdescribed here are merely intended to illustrate selected embodiments,not all possible embodiments, and are not intended to limit the scope ofthe content disclosed herein.

FIG. 1 is a perspective view of a heat dissipation device according tosome embodiments of the present invention.

FIG. 2 is a perspective view of a heat dissipation device according tosome embodiments of the present invention, wherein a pressure plate isnot shown.

FIG. 3 is a sectional view of a heat dissipation device according tosome embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Preferred embodiments according to the present invention are explainedin detail below in conjunction with the drawings. Those skilled in theart will gain further understanding of the characteristics andadvantages of the present invention through the drawings and thecorresponding explanatory text. Obviously, the embodiments described aresome, not all, of the embodiments of the present invention. Generally,components of embodiments of the present invention that are describedand shown in the drawings here may be arranged and designed in variousconfigurations.

In the description of the present invention, a direction or positionrelationship indicated by terms like “top”, “bottom”, “up”, “down”, etc.is based on a direction or position relationship shown in a drawing, oris a direction or position relationship in which the invention productis usually placed when used, or is a direction or position relationshipusually understood by those skilled in the art; it is intended only forconvenience of description of the present invention and brevity ofdescription, instead of indicating or implying that the device orcomponent in question must have a specific direction or be constructedand operated in a specific direction, and therefore should not beconstrued as limiting the present invention.

FIG. 1 shows a heat dissipation device 2 for an electronic component 1according to the present invention. The electronic component 1 is acircuit component part of an electronic apparatus. In some embodiments,the electronic apparatus is for example an onboard AC-DC converter orDC-AC converter or DC-DC converter; these electronic apparatuses oftengenerate large amounts of heat with high currents. However, it should beunderstood that the heat dissipation device 2 according to the presentinvention may also be used in other industrial fields including consumerelectronics, household appliances, engineering machinery and electricalapparatuses.

As shown in FIG. 1 , the electronic apparatus comprises a housing 7 anda printed circuit board (not shown) accommodated in the housing 7. Forconvenience of description, only part of the electronic apparatus isshown in FIG. 1 . At least one electronic component 1 is electricallyconnected to the printed circuit board by means of pins for example. InFIG. 1 , the number of electronic components 1 is 4 for example. Theelectronic component 1 is for example a power semiconductor device, suchas a MOSFET, which during use will consume a portion of energy andconvert this to a large amount of heat, with the result that theelectronic component 1 heats up, and the junction temperature rises. Forthis purpose, at least one electronic component 1 shall be provided witha heat dissipation device 2, as described in detail below.

The heat dissipation device 2 comprises a heat dissipating component 20,also called a heat sink, arranged at a lower side of the electroniccomponent 1. The heat dissipating component 20 can undergo heat exchangewith the electronic component 1 and absorb the heat generated by theelectronic component 1 during operation, to lower the temperature of theelectronic component 1. In some embodiments, the heat dissipatingcomponent 20 is formed as a portion of the housing 7, as shown in FIG. 3. In other embodiments, the heat dissipating component 20 and thehousing 7 are formed as separate components.

The heat dissipation device 2 may comprise a heat conducting layer 50arranged between the heat dissipating component 20 and the electroniccomponent 1, to promote heat exchange between the heat dissipatingcomponent 20 and the electronic component 1.

As best shown in FIGS. 2 and 3 , the heat dissipation device 2 comprisesat least one elastic element 30, arranged at an upper side of theelectronic component 1, i.e. at the side opposite the heat dissipatingcomponent 20.

As best shown in FIGS. 1 and 3 , the heat dissipation device 2 furthercomprises a pressure plate 40, arranged at an upper side of the at leastone elastic element 30, such that the at least one elastic element 30 isheld between the pressure plate 40 and the at least one electroniccomponent 1. The pressure plate 40 is connected to a fixed structure.The at least one elastic element 30 is compressed between the pressureplate and the at least one electronic component 1, thereby applyingpressure to the electronic component 1 in the direction of the heatdissipating component 20.

This configuration according to the present invention can avoid thedirect application of a rigid action force to the electronic component1, preventing the electronic component 1 from experiencing localconcentrated strain and thereby being damaged. In addition, since thepressure plate 40 is connected to the fixed structure, as time passes,the elastic element 30 can still apply a sufficient elastic action forceto the electronic component 1, thereby forming stable and reliablethermal contact between the electronic component 1 and the heatdissipating component 20.

In some embodiments, the fixed structure may be a portion of the printedcircuit board.

In some embodiments, the fixed structure may be a portion of the housing7 of the electronic apparatus.

In some embodiments, the fixed structure may be a portion of the heatdissipating component 20.

In some embodiments, the fixed structure may be a portion of the heatdissipating component 20, and the heat dissipating component 20 may beconnected to the housing 7 of the electronic apparatus.

The fixed structure is a portion of the housing 7 of the electronicapparatus or the fixed structure is a portion of the heat dissipatingcomponent 20, and the heat dissipating component 20 may be connected tothe housing 7 of the electronic apparatus. In these two configurations,the pressure plate 40 is directly or indirectly fixed to the housing 7of the electronic apparatus. This is especially advantageous in the casewhere the electronic apparatus is an onboard electronic apparatus, suchas an onboard AC-DC converter or DC-AC converter or DC-DC converter. Therunning of a motor vehicle will be accompanied by vibration of theonboard electronic apparatus; such vibration might cause loosening ofthe thermal contact between the electronic component 1 and the heatdissipating component 20, thereby weakening the heat dissipation effect.Having the pressure plate 40 directly or indirectly fixed to the housing7 of the electronic apparatus enables the positioning of the pressureplate to be more reliable, thereby resisting the adverse effect ofvibration on thermal contact.

In some embodiments, the pressure plate is firmly attached to the fixedstructure. It is possible to use an almost permanent connection (e.g.welding, adhesive, riveting, etc.), or a removable connection with oneor more fasteners (e.g. a screw, bolt, snap-fit connection, etc.). Asshown in FIGS. 1 and 2 , the pressure plate 40 is fixed to the fixedstructure by means of screws 80, and the action force applied to theelectronic component 1 by the at least one elastic element 30 can beadjusted by adjusting the screws 80.

In some embodiments (not shown), the elastic element is a coil spring,which is made of a metal material for example.

In some embodiments (not shown), the elastic element is an elastic pad,which is made of an elastic material for example.

In some embodiments, the elastic element is plate-like with an arcuateshape overall, and comprises a top portion 31 and two branch portions 32extending from the top portion 31, as shown in FIGS. 2 and 3 . Theplate-like elastic element 30 is made of metal for example. The heatdissipation device 2 may comprise an electrical insulation sheet 60arranged between the elastic element 30 and the electronic component 1.The top portion 31 of the plate-like elastic element 30 abuts thepressure plate 40; the branch portions 32 of the plate-like elasticelement 30 are supported on the electronic component 1 via theelectrical insulation sheet 60. As shown in FIG. 3 , the electronicapparatus comprises four electronic components 1 and two plate-likeelastic elements 30. Each plate-like elastic element 30 is allocated totwo adjacent electronic components 1, with one branch portion 32 thereofbeing supported on one electronic component 1 via the electricalinsulation sheet 60.

In some embodiments, the plate-like elastic element 30 and the pressureplate 40 are both made of metal, e.g. 301 stainless steel. The thicknessof the plate-like elastic element 30 is in the range of 0.6 mm to 1 mm.The thickness of the pressure plate 40 is in the range of 2 mm to 3 mm.The plate-like elastic element and pressure plate in the above thicknessranges can supply a sufficient action force to the electronic component,to achieve reliable thermal contact between the electronic component andthe heat dissipating component.

In some embodiments, the pressure plate 40 or the housing 7 comprises afirst positioning structure configured to cooperate with a secondpositioning structure of the at least one elastic element 30; theelastic element 30 can thereby be held in place, so as to apply a stableelastic action force to the electronic component 1, and thereby ensuregood thermal contact between the electronic component 1 and the heatdissipating component 20. In addition, the cooperation of the firstpositioning structure and second positioning structure also enables theelastic element and pressure plate to be fitted together more easily.

In some embodiments, as shown in FIG. 2 , the first positioningstructure is a notch 71 in the housing 7, and the second positioningstructure is a protrusion 33 of the plate-like elastic element 30; theprotrusion 33 of the plate-like elastic element 30 is configured to bereceived in the notch 71 of the housing 7. Thus, the position of theelastic element 30 can be held relative to the housing, and a mountingposition can be quickly determined in the process of fitting the elasticelement.

In some embodiments (not shown), the first positioning structure is arecess formed in the pressure plate 40, and the second positioningstructure is the top portion 31 of the elastic element 30; the topportion 31 is configured to be received in the recess of the pressureplate 40. Thus, the position of the elastic element 30 can be heldrelative to the pressure plate, and since the pressure plate is fixedrelative to the housing or the heat dissipating component, the elasticelement is also not easy to move relative to the heat dissipatingcomponent, and can thereby apply a stable action force to the electroniccomponent.

Of course, those skilled in the art will also be able to envisage otherpositioning structures to hold the elastic element in place. Forexample, in the case where the elastic element is a coil spring orelastic element, a receiving seat for the coil spring or elastic elementmay be provided in the pressure plate, the receiving seat being matchedin shape to the coil spring or elastic element.

The heat dissipation device proposed in the present invention alsoadvantageously simplifies manufacturing and assembly process steps. Inprior art in which an elastic clip is used, in order to enable theelastic clip to apply a sufficient action force to the electroniccomponent, it is often necessary to complete a process step of elasticclip deformation with the aid of an automatic press machine, and this istime-consuming and laborious. In the present invention, all of theassembly process steps can be completed at one workstation; all thatneed be done is to stack the heat conducting layer, electroniccomponent, electrical insulation sheet, elastic element and pressureplate in sequence and then fix the pressure plate. The operation issimple and convenient, and there is no need for an additionalinstallation apparatus to be introduced.

Further features of the present invention can be found in the claims,the drawings, and the description of the drawings. The features andfeature combinations mentioned in the specification above and thefeatures and feature combinations further illustrated in the drawingsand/or shown independently in the drawings are not only used for thecombinations that are respectively indicated, but also used in othercombinations or independently used, without violating the scope of thepresent invention. Details of the present invention that are notexplicitly shown and explained in the drawings but emerge and can beproduced from explained details through independent feature combinationsthus become included and disclosed. Thus, details and featurecombinations that lack all of the features of the independent claimsoriginally formed should also be regarded as being disclosed.

1. A heat dissipation device for an electronic component, the heatdissipation device comprising: a heat dissipating component disposed ona first side of the electronic component; at least one elastic elementarranged on a second side of the electronic component opposite the firstside; a pressure plate arranged such that the at least one elasticelement is located between the pressure plate and the electroniccomponent, the pressure plate being connected to a fixed structure toapply pressure to the electronic component via the at least one elasticelement in the direction of the heat dissipating component.
 2. A heatdissipation device according to claim 1, wherein said electroniccomponent is accommodated in a housing and electrically connected to aprinted circuit board, and wherein said fixed structure is a portion ofthe heat dissipating component or of the housing or the printed circuitboard.
 3. A heat dissipation device according to claim 1, wherein thepressure plate is firmly attached to the fixed structure.
 4. A heatdissipation device according to claim 1, wherein said at least oneelastic element has generally an arcuate shape and comprises a topportion and two branch portions extending from the top portion.
 5. Aheat dissipation device according to claim 1, wherein the at least oneelastic element is a coil spring or an elastic pad.
 6. A heatdissipation device according to claim 2, wherein the pressure plate orthe housing comprises a first positioning structure configured tocooperate with a second positioning structure of said at least oneelastic element.
 7. The heat dissipation device according to claim 6,wherein the first positioning structure is a notch in the housing, thesecond positioning structure is a protrusion of the elastic element, andthe protrusion of the elastic element is configured to be received inthe notch of the housing.
 8. The heat dissipation device according toclaim 6, wherein: the at least one elastic element has generally anarcuate shape and comprises a top portion and two branch portionsextending from the top portion, and the first positioning structure is arecess formed in the pressure plate, the second positioning structure isthe top portion of the elastic element, and the top portion isconfigured to be received in the recess of the pressure plate.
 9. Theheat dissipating device according to claim 1, further comprising: a heatconducting layer arranged between the heat dissipating component and theelectronic component.
 10. The heat dissipation device according to claim1, further comprising: an electrical insulation sheet arranged betweenthe at least one elastic member and the electronic component.
 11. A heatdissipation device according to claim 4, wherein the at least oneelastic element is made of metal.
 12. A heat dissipation deviceaccording to claim 1, wherein the electronic component is a MOSFET. 13.An AC-DC converter or a DC-AC converter or a DC-DC converter comprisingthe heat dissipation device according to claim
 1. 14. The AC-DCconverter or DC-AC converter or DC-DC converter according to claim 13,wherein said AC-DC converter or DC-AC converter or DC-DC convertercomprises a housing, and wherein the fixed structure is a portion of thehousing, or the fixed structure is a portion of the heat dissipatingcomponent and the heat dissipating component is connected to thehousing.
 15. A motor vehicle comprising the AC-DC converter or the DC-ACconverter or the DC-DC converter according to claim 13.